This invention relates to resinous binder compositions which are admixtures of amine-based polyols and polyisocyanates. In another aspect this invention relates to curable urethane binder compositions which are useful for binding particulate solids. In particular the invention relates to binders, of the No Bake type, which utilize an amine polyol. The binders are capable of bonding sand or other foundry aggregate to form molds or cores for casting of metals, especially aluminum and other light weight metals which are cast at relatively low temperature. The cores and molds made using these binders demonstrate superior collapsibility when used at low casting temperatures.